The force of the argument "I don't want to be a really big integer" is that "being wireheaded takes away what makes me me, and so I stop being a person I can identify with and become a really big integer". If that were so, the same would apply to anti-wireheading, and Wei Dai's question would apply. If you agree that wireheading is more desirable than anti-wireheading, then this and other arguments that it's not more desirable than any other state don't directly apply.